W0010: effect fires on every tick where condition is true

Generated from rellum-diagnostics/src/db.rs.

Explanation

Subscribing an effect to a Bool-typed graph node means the effect fires on every tick where that value is true and its inputs changed - not only when it first becomes true. This is level-triggered behavior. If you want edge-triggered behavior, track the previous value explicitly.

Common causes

• subscribing an alert or notification effect to a threshold comparison
• using on exceeded where exceeded is a Bool derivation

Canonical fixes

• track the previous value to detect the rising edge

Before:

alert! on exceeded => send!(...)

After:

was_exceeded ~ feedback(
    on sensor => exceeded,
    false
)
alert! on sensor =>
    match was_exceeded
        false => send!(...)
        true => ()

Code example

alert! on exceeded => send!(...)

Links

• RellC diagnostic overview